This invention relates to devices, including orthopedic braces and splints, for the shoulder joint and arm where it is generally but not exclusively desired to provide a fixed position for the arm relative to that joint. These devices are generally referred to by those skilled in the art as braces or orthoses. Many joint injuries and treatments require an orthosis of a type which provides early controlled motion through a pre-selected range after or in conjunction with other treatment. The shoulder joint is no exception to this general rule. However, there are also many conditions and treatment modalities where early mobilization is not favored and rigid immobilization is used, placing the arm and the joint in carefully selected relative positions during a period of rehabilitation following injury or surgery.
Both mobilizing and immobilizing orthoses must, necessarily, be designed with architecture appropriate to the normal physiological limits of angular travel of the joint to be treated and to the linear travel of associated limbs and the planes in which this occurs. These considerations should dictate the limits of movement and adjustment to be provided by the orthosis. The normal shoulder joint is capable of movement in multiple planes and this increases the degree of difficulty for the orthosis designer, especially since it is generally required to include control of the arm. This is necessary because the arm can exert considerable leverage at the shoulder joint. Shoulder joint movements include flexion, extension, abduction, adduction and internal and external rotation. All are possible over a large angular range and in numerous combinations. On the other hand the shoulder joint is not weight bearing in the sense that the knee or hip are compressively loaded and this does confer some design latitude.
Until recently, orthotic design for the lower limb was more intensive and wide ranging than for the upper limb. The reasons are fairly obvious in that structural or dynamic failure of the hip or knee directly impairs or prevents mobility. Similar failure in the upper limb leads to severe but less disabling sequelae. Notwithstanding this, there are numerous injuries due to trauma and overuse which can, in damaging the upper limb, markedly restrict or incapacitate the sufferer. A damaged shoulder can, for instance, make dressing, driving or writing difficult or even impossible.
Treatment of shoulder injuries by arthroscopic surgical techniques has grown rapidly over the last decade and leading authorities predict that surgical advances will continue for some years to come. The public, including the older patient population, now has increased expectations of a satisfactory functional resolution of shoulder joint problems. The trend of increasing demand for surgery on the shoulder, together with adjunctive treatment, will probably be maintained and this should be seen against the fact that even by 1989, the shoulder was indicated by the American Academy of Orthopaedic Surgeons as the reason for 14% of all consultations leading to surgery.
The present invention is concerned with conditions of the shoulder which, whatever the primary method of treatment, are managed post-operatively or following injury mainly by immobilization in a selected position but where, in some cases or at some stages, an option for early mobilization of the forearm would be useful. Recurrent posterior subluxation of the shoulder is an example of a condition which is often treated by surgery, usually followed by a period of immobilization.
A need exists for an orthosis which is light and stable and in which adjustments can be made in a continuously variable manner in relation to all directions of movement which occur in the human shoulder. Such an orthosis should provide sufficient linear adjustment for the arm to induce angular displacement of the shoulder joint to any selected position over a large clinically useful range. It is desirable that such an orthosis should be wearable while ambulatory but also readily tolerable while sitting or lying in bed. It to these needs that the present invention is directed.
The simplest orthoses which provide immobilization of the shoulder fall into two categories. Abduction pillows, as the name implies, provide abduction at a more or less fixed position and an example of this type, though not the simplest realization, is disclosed in Scott, U.S. Pat. No. 4,896,660. Orthoses of this type are bulky and can inconvenience the ambulatory patient, particularly in restricted places such as doorways. However, abduction is not always required and simple shoulder immobilizers, which comprise a cotton or canvas sling for the lower arm and elbow together with suitable straps, are frequently used in relatively straightforward situations. Examples of this type, though once again not the simplest, include Scott, U.S. Pat. No. 4,878,490 and Florek, U.S. Pat. No. 4,480,637.
A more complex class of shoulder orthoses might be called the "pylon" type. This class is provided with a waist-worn member upon which a generally upwardly directed bar or pylon is mounted. A suspension harness is worn on the contra-lateral shoulder and a mechanism is positioned in the axilla in order to provide support and positioning means for the shoulder joint. The axillary mechanism sometimes also provides means for control over a selectable range for one or more motions of the shoulder. The earliest example of this general type we have found was disclosed in Maddox, U.S. Pat. No. 1,340,630 in 1920 and other examples and variants include Brudny, U.S. Pat. No. 4,417,569 and Johnson, U.S. Pat. No. 5,360,391. The use of a pylon proximate the trunk and an axillary mechanism is also sometimes seen in continuous passive motion apparatus for the shoulder as in Funk, et al., U.S. Pat. No. 4,651,719.
The authors of the present invention have previously been granted letters patent (U.S. Pat. No. 5,033,461, EPO 0,404,362 and U.S. Pat. No. 5,046,490) in respect of various devices for bracing and providing control of movement at the shoulder. The mechanisms described therein have been used commercially in a shoulder orthosis for the control of movement in a continuously variable manner, in the included angle between the arm and the trunk. The device is made by Protectair Limited of Abdingdon, U.K. and is sold under the name Masterhinge.RTM. Shoulder Brace. The gross morphology conforms to the general description of a "pylon" type orthosis outlined above.
Other orthoses of this general type include two shoulder positioning devices made by United States Manufacturing Company of Pasadena, Calif., U.S.A. The products are known commercially as the SASI.RTM. and SASII.RTM.. They offer positioning but not control of range of motion in abduction and adduction.
Another shoulder orthosis of this type is made by Donjoy Inc. of Carlsbad, Calif., U.S.A. and is sold under the commercial name Quadrant.RTM.. This orthosis provides adjustment for position of the shoulder in abduction but does not provide for controlled movement in abduction.
A "pylon" type orthosis is known to have been offered by Hug GmbH, Germany in the late 1980's and employed a rubber compression element in the axilla. Some abduction movement appears to have been possible but so far as is known, this was not over a controlled range.
The earliest commercial product of the "pylon" type we are aware of was an orthosis believed to have been made by Durr-Fillauer Incorporated of Chattanooga, Tenn., U.S.A. and possibly called the Toronto Shoulder Orthosis. This offered selected fixed shoulder positions in abduction and free movement or a fixed position in flexion.
Another class of shoulder immobilizing orthoses might be referred to as the "non-pylon" type. Members of this class do, generally, have a waist-worn member but they do not have a pylon and axillary mechanism. This is the general class to which the present invention belongs.
One example is made by the United States Manufacturing Company of Pasadena, Calif., U.S.A. and is sold under the commercial name Gunslinger.RTM.. This orthosis does not provide abduction positioning whereas a variant, called the GunslingerII.RTM., employs an outrigger by means of which 45.degree. of abduction may be achieved. However, this latter orthosis appears to be recommended for abduction only. Both versions employ manually tightened screw clamps which require considerable tightening torque and therefore strength in order to achieve stability of adjustment. There are two adjustments which appear to allow or affect shoulder rotation. One adjustment employs a simple, manually tightened, screw operating a pinch clamp on a circular-section spigot. The clamp might be vulnerable to under-tightening which could lead to instability on the circular mount. This would be undesirable in a shoulder joint which had recently been operated upon. The other adjustment involves a substantially circular plate which can be moved along concentric slotted paths, close to its circumference and is manually secured by tightening two screw clamps. The spigot of the first referred to adjustment is mounted on the circular plate near its edge close to what is, effectively, the upper pole thereof. It seems inevitable, therefore, that any adjustment along the circular path which the plate must follow will produce a variable displacement of those parts of the device which support the forearm. This will cause the position of the shoulder joint to be varied with both a vertical and either an anterior or posterior component, at the same time. It is difficult to relate this compound adjustment to the anatomy of the structures presumably under treatment and to any direct physiological requirement.
In Burkhead, et al., U.S. Pat. No. 5,385,536, there is disclosed another "non-pylon" device which has an outrigger arrangement. This has a waistband (described as a saddle) secured on the waist with straps and stabilized with a contra-lateral shoulder strap. The saddle is provided with a discontinuous vertical mounting rack for a positioning rod. The positioning rod is used for varying the elevation of the arm with coarse and fine adjustments for length and it has universal joints at the upper and lower ends. A single axis elbow hinge has arms which may be locked with a pin and means are provided for retaining both the upper and lower arm. Means for retaining and supporting the hand and wrist are not disclosed. Coarse adjustment of the length of the positioning rod, which has telescoping inner and outer elements, is discontinuous and is effected by means of a locking pin traversing both elements. The lower ball joint is locked by a compression nut and locking of the upper ball joint is by compression delivered by means of threadedly compressing two elements of a socket housing against the ball with another nut.
Ball joints as a means of positioning a joint are notorious in the art of orthotics for their tendency to be unstable and to lose position. This is especially so where narrow circular line contacts are employed between the ball and the locking means, as in the case of the lower ball joint employed in the Burkhead device. In the art, ball joints are normally chosen in situations where it is not necessary or not desirable to lock or block movement at a particular position. Where they are chosen and must be locked, a substantially enclosed design is normally selected, however, this tends to limit the angular operating range of the mechanism because so much of the ball is within a housing. In this case, the need to achieve a large angular range of adjustment is clear. That stability is also recognized as important may explain why relatively massive locking nuts are illustrated for the preferred embodiments--much bigger across flats than the diameter of the ball of the joint. The risk is that these may be over-tightened with a significant possibility of damage or excessive wear to components. An additional limitation of the Burkhead device is that the positioning assembly requires a substantial minimum length in order to achieve worthwhile elevation of the arm in a large population of patients. This must necessarily limit the capacity for the arm to be brought close in to the body with the shoulder abducted. It also partially negates one purpose of a vertical positioning mount on the saddle which presumably is to accommodate variation in the length of the humerus. Finally, as with the Gunslinger.RTM. device, described above, movement of the forearm into scandent or dependent positions appears to involve compound adjustment of the shoulder joint position, in this case due to the upper ball joint being distanced from the position of the elbow joint by an element called an arm.
Williams, U.S. Pat. No. 3,952,733 discloses an arm support which in some respects appears to be a hybrid of the "pylon" and "non-pylon" types of orthosis.
Considering other types of device in the art, in Lipton, U.S. Pat. No. 5,000,168, there is disclosed a portable limb supporter which employs two or more, telescoping, discontinuously adjustable, positioning assemblies, the upper and lower ends of which are pivotally attached to other elements by yoke joints. Stability on the waist would appear to be limited and there are no apparent means for medial and lateral adjustment.
A hand forearm support disclosed by Meals, U.S. Pat. No. 4,807,609, appears to accommodate rotation of the forearm which may well allow rotation at the shoulder, however, means for elevating the arm are not disclosed and the use of a support for this purpose, such as table, is required.
In U.S. Pat. No. 5,231,998, there is disclosed an orthosis for dampening limb tremors which allows functional activities of the arm, over a range of motion, in a seated patient. The device requires a support, such as a wheelchair and means for attachment to the body are not disclosed. This patent is particularly directed towards sensor and braking means for an orthosis with multiple degrees of freedom and is referenced as of general interest to those active in the art of orthotics for the upper limb.
The present invention provides an improved shoulder and arm positioning orthosis to be used following injury or surgery. In the invention, a novel arrangement between a rise and fall mount, a pivoting slide and a forearm support assembly induces a very large angular range of positions for the shoulder joint in a plurality of planes by providing a large and continuously variable linear range of adjustment for the arm. Additionally and optionally, the orthosis of the present invention provides for controlled movement of the forearm over a selectable range. The orthosis of the present invention is light and particularly provides for improved ease of adjustment and stability in an ambulatory patient and may also be worn while sitting or lying down.
According to a first aspect of the invention, there is provided an orthosis for the human shoulder joint and arm which provides securing means having buckle, strap harness, belt, buckle, strap and lining means for securing it to the human body in a stable, secure and comfortable manner.
According to an important aspect of the invention, there is provided a stable rise and fall mount, for other functional elements of the orthosis, which is secured to the waistband and as the form of two, similar, slotted metal bars in substantially parallel and vertical alignment, together with a third metal bar in the form of an asymmetrical, angled bracket. The angled bracket, which has a slotted, laterally disposed and an antero-posteriorly directed portion is adapted for receiving adjustable attachement means for adjustably securing it, disposed in substantially horizontal manner, to each of the vertical bars. Adjustable securing means are conveniently but not necessarily, in the form of lever-operated, pre-set, quick-release, over-center clamps attached, not-releasably, by bolt means. By slackening the clamps, the angled bracket may be moved, in a continuously variable manner, to any position within the slots of the vertical bars, after which the clamps are re-tightened. Other elements of the orthosis and an arm held within it may thus be located at a selected position in the vertical plane.
According to another important aspect of the present invention, there is provided a metal pivoting slide having a generally disposed pivoting plate and a lateral slide support. The pivoting slide is centrally, pivotally and non-releasably secured to the slot of the angled bracket of the rise and fall mount with a pivot bolt. The pivoting plate is provided with an arcuate slot.
Bolt means, disposed within the arcuate slot and the slot in the angled bracket, threadedly and non-releasably engage with adjustable securing means, similar to those employed in the rise and fall mount and thereby secure the latter to the pivoting slide. Spacing means, disposed between the pivoting plate and the angled bracket, prevent interference between elements of releasable securing means and other parts of the mechanism. The elements of the pivoting slide cooperate with the rise and fall mount to provide pivotal and antero-posterior adjustment means for a forearm support assembly mounted upon the lateral slide support. By slackening releasable securing means, the pivoting slide and forearm support assembly may be positioned, in a continuously variable manner, at any point along the slot of the angled bracket of the rise and fall mount. These elements may also be moved pivotally, in a continuously variable manner, about the axis of the pivot bolt, to provide a plurality of scandent and dependent positions for a human forearm.
According to another important aspect of the present invention, a forearm support assembly has a slotted, metal travelling support bar, upon which is mounted a lined forearm retaining shell and to which is attached a hand support assembly. Straps pass around the forearm shell to secure the forearm. The travelling support bar is non-releasably secured to the lateral slide support of the pivoting slide with bolt means and adjustable securing means. Bolt means engage intimately with the slot in the travelling support bar and non-intimately with the slots of the lateral slide support. The slots, adjustable securing means and bolt means co-operate to provide a wide and continuously variable range of slidable and lockable adjustment for the forearm assembly of the orthesis. This arrangement, in conjunction with the rise and fall mount, allows the shoulder joint to be abducted to 45.degree. or to be fully adducted. Additionally, anterior, posterior, inswing and outswing adjustments for the arm over a large linear range are possible. A hand support assembly is adjustably, slidably and non-releasably secured to the travelling support bar with bolt means and adjustable securing means. The hand support assembly has a slotted metal hand support bar and a hand support, such as a suitably sized sphere. The hand support assembly, in conjunction with other elements of the forearm support assembly, provides slidably adjustable and lockable means for comfortable positioning for a hand and wrist within the orthosis.
According to another aspect of the present invention, the additional, optional provision of adjustable abutment stop means in the arcuate slot above and below adjustable securing means allows controlled movement of the pivoting plate and hence for a forearm secured within a forearm support assembly.
Within the present invention, the mechanical and geometrical relationship between the components of a rise and fall mount, a pivoting slide and a forearm assembly, particularly slots therein, together with the provision of adjustable securing means, cooperate to allow continuously variable, stable positioning of a human shoulder joint in flexion, extension, internal and external rotation, abduction and adduction or combinations thereof. All may be achieved over a large angular range and in an easy manner. In addition, components are so sized that mutual adjustment between them is adequate to accommodate a very wide range of patient sizes and shapes with a single orthosis for a right arm and shoulder and a single orthosis for a left arm and shoulder.
It is, therefore, an object of the present invention to provide an orthosis for immobilizing an arm and shoulder which will allow the shoulder joint to be positioned accurately over a broader and larger range of angular positions including in flexion, extension, internal and external rotation, abduction and adduction or rational combinations thereof, than with the prior art orthoses.
It is another object of the present invention to provide an orthosis for an arm and shoulder which will allow the arm to be positioned accurately over a larger linear and angular range than with prior art orthoses.
It is another object of the present invention to provide an orthosis for an arm and shoulder which will allow the arm, elbow joint and shoulder joint to be positioned more stably than with prior art orthoses.
It is yet another object of the present invention to provide an orthosis for an arm and shoulder, the adjustable elements of which can be unlocked, adjusted and re-secured easily and without the need for great strength.
It is yet another object of the present invention to provide an orthosis for an arm and shoulder which will, optionally, provide controlled movement for the forearm.
It is yet another object of the present invention to provide an orthosis for an arm and shoulder which will fit the great majority of patients with a single left size and a single right size.
Other features, objects and advantages will become apparent from the specification and drawings.